Internal combustion engine



Oct. 25, 1932. A. A. WIDMANN 1,884,450

- INTERNAL COMBUSTION ENGINE Filed Oct. 10, 1951 g 1 1 001 x i (11-;

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wa 0a. 25, 1 32 UNITED STATES PATENT OFFICE ADOLI' A. WIDIANN, 0F DETROIT, MICHIGAN, ASSIGNOR 'I'O HEBMANN I. DOBNEB,

. OF DETROIT, MICHIGAN INTERNAL COMBUSTION ENGINE Application filed October 10, 1931. Serial Io. 588,170.

This invention relates to apparatus for starting internal combustion engines, and more particularly to engines employing ignition means of the incandescent type, commonly referred to as glow plugs.

Diiiiculty has heretofore been encountered in the design of glow plugs to enable them to function properly for a longer period than a few hours. It has been found that the high temperature to which the incandescent element must be raised, this temperature being increased by the heat of the engine, together with the excessive vibration induced in the incandescent element by the motor explosions and other regular impulses result in the rapid deterioration and breakage of the element.

The glow plug has nevertheless been found extremely useful in internal combustion engines of the compression ignition type, since a separate igniter is required only during starting of the engine and thus an ignition device which is capable of use for only a few hours willserve the purpose. Furthermore, it is found that in engines operating on the Diesel cycle and burning fuel oil, the spark plug fails to give sufiicient heat and to distribute that heat over a sufiiciently wide areato ensure proper ignition of the cold fuel mixture instarting the engine.

Thus it is important to conserve the life of the incandescent element by ensuring that this element will be energized for a short period of time only when starting the engine in order to lengthen the life both of the plugs and the battery by means of which they are energized. This may, of course, be taken care of by the operator when a separate switch is provided for energizing the glow plugs, but it is preferable to eliminate the personal element and to ensure that the plugs will be energized for a predetermined period only each time the engine is started.

It is furthermore found desirable to maintain the ignition means in operation for a brief interval of time after rotation of the engine has been initiated by the starter and the firing of the combustible mixture has commenced sineethis mixture is still relatively cold and stalling of the engine after the starter has ceased to function may result.

It is therefore an object of the present invention to provide time controlled means for determining the period during which the ignition means remams active at each starting operation.

A more specific object of the invention is the provision of means whereby the starter and the ignition means may be simultaneously energized and whereby the duration of energization of the ignition means is determined independently of the means which initiates the energization thereof.

A further object of the invention is the provision of a single switch for rendering the starter and ignition means simultaneously operative and time controlled mechanism for thereafter rendering the ignition means inoperative.

Preferably the arrangement is such that relay elements may serve'for the control of the main circuits supplying current to the starter and the ignition means since both starters and ignition means of the incandescent type require a relativel heavy current. It is thus possible to avoi the premature burning out of the contact-making devices in the circuit.

' It is a further object of the invention to provide means whereby the length of time of energization of the plugs will be materially reduced when the engine is. warm, for

instance when it is found necessary to stop and restart the engine. In this way the life of tile plugs and the battery may be lengthene Y Further objects and features of the invention will be apparent from the following description taken in connection with the accompanying drawing, in which Figure 1 is a diagrammatic illustration of one arrangement of electrical circuits for controlling a starter and ignition means in accordance with the principles of the invention; and

. Figure 2 is a similar diagrammatic illus- Referring more specifically to 1 of the drawing, it will be observed that a source of current supply 10, preferably a battery having one pole grounded as shown, serves to energize the starter 11 and the lgmtlon ,means 12. A current controlled switch or relay 15 is interposed betweenthe other pole of the battery and the starter 11 and a second current controlled switch 16 is interposed between the battery and the ignition means 12.

The opposite lead from the starter is grounded on the engine or engine support at 17 and the ignition means, which inthe preferred form of the invention, are of the incandescent or glow plug type, are groundedat 18 in the conventional manner. Thus when the current controlled switches 15 and 16 are closed,-

a heavy current will flow through the starter lland the glow plugs 12.

A starter switch 19, consisting of a movable contact arm 20 and fixed contacts 21 and 22 is provided, the movable contact being grounded as indicated at 25 and being arranged to engage the fixed contacts in the closed position of the switch.

The fixed contact 21 is connected through the winding .26 to the battery 10 and thus when this contact is grounded by closing the starter switch, the relay is energized to bridge the contacts 28, 29 in the main starter circuit foroperating the starter. It will be observed that the control circuit for the starter 'is entirely independent of the circuits which control the ignition means.

The main circuit for the ignition means comprises the fixed contacts 31, 32 which are arranged to be bridged by the movable contact 33 when the relay 16 is operated by energizing the winding 35. One side of this winding is connected to a pair of fixed con tacts 34 associated with a movable contact 36 normally engaging a fixed contact 37 and movable into engagement with a second fixed contact 38 onactuation of therelay. The

fixed contact 37 is connected to the fixed contact 22 of the starter switch and fixed con:

tact 38 is grounded preferably by connection to the movable contact 20 of the starter switch. The other side of the winding" of the relay 16 is connected to the fixed contact 40 of a time controlled switch 41, preferably of the thermostatic type, this contact -normally engaging the movable contact 43 of the switch which is mounted on and electrically connected with a. bi-metallic element 45 having one end thereof rigidly mounted heating coil 4:8. The heating coil 48 surrounds the bi-metallic element and is connected at one end thereto, the other end being connected to the winding 35 of the relay 16 so that this windin .and the heating coil terIy. I

t will now be observed that when the starter switch is closed the fixed contact 22 of the switch is grounded and current flows through the contacts 36 and 37 and through the winding 35 of the relay 16 and the heating coil 48 of the time controlled switch to the battery. Thus the relay 16 is energized, the contacts 31 and 32 of themain circuit of the ignition means are bridged and simultaneously the movable contact 36 is shifted from engagement with the contact 37 to the contact 38, the circuit including the winding of the relay 16 being thereby again grounded by a by-pass' around the starter switch. Thus if the starter switchisaopened, the relay 16 will remain energized and the main circuit for the ignition means will remain closed, although operation of the starter has been discontinued. When the bimetallic element 45 has been sufficiently heated by the coil 48, the contacts 43 and 40 will separate and the circuit contnolling the relay 16 will be opened, thus permitting the relay'to assume its original position with the main ignition circuit opened. 5

In this manner the ignition means are automatically controlled so as to supply heat to the cylinder for a predetermined eriod of time, this period being preferably on er than-that normally required for the starting of the engine.

By reason of the high degree of compression it is ordinarily preferable to start Diesel motors by storing up the energy of the starter motor in a fiy-wheel which is clutched to the engine after being brought to the proper speed. It will nevertheless be observedthat the present arrangement is a plicable regardless of whether the centriiiigal type of starter is used or whether the starter motor is connected directly to the engine.

Referring now to Figure 2 of the drawing, in which similar refer-nee, numerals have been used to indicate similar parts, it will be observed that the starter 11 and glow plugs 12 are arranged to be connected to the same side of the source of current supply 10, the opposite sideof this source being grounded as indicated at 70. Two relays or current Y able contact 76 being connecte through the lead 78 to they winding for the relay 72 and thence to the ground 80 for the starter. The other lead from the starter is connected to one of a pair of fixed contacts 81, 82, the other'contact being connected to the current source 10, which are arranged to be bridged bglthe movable contact. 84 of the relay 72.

us, closi of the starter switch 76 energizes the're ay 72 to supply current to the starter 11. The source of current supply 10 is also connected by a lead 85 to one of a pair of fixed contacts 87, 88 which areal-ranged to be bridged by a movable contact 90 of the relay 73 to supply current to the glow plugs 12. The remaining movable contact 92 of the double pole switch 7 5 is connected to one end of the winding of the relay 73, the other end of this winding being grounded, as indicated at 94. The closin of the starter switch 75 therefore com etes the circuit through the lead 85 to t e glow plugs 12 which remain ignited as long as the winding of the relay 7 3 is energized.

If the starter switch 7 5 is now opened, the winding of the relay 72 will he de-enerd, permitting the movable contact 95 to move to p the position shown in Figure 2 bridging the contacts 96, 97, one of which is connected to the source of supply 10 and the other of which is connected through a time controlled switch indicated generally at d1 to a fixed contact 98. A fixed contact 99, connected to the movable arm 92 of the starter switch and to one end of the winding for the relay 73 is an ranged to be connected by a'movable contact 101 of the relay to the fixed contact 98. Gurrent will then flow from the source of supply through the contacts 96, 95, 97 and through the time controlled switch 41 and the contacts 98, 101 and 99 to thewinding for the relay 73 and thence to the ground 9d. It will be observed that although the starter switch 7 5 has been opened, an auxiliary circuit has been es tablished supplying current to the winding of the relay 7 3 so that this relay is maintained in such position that the contacts 87 and 88 are bridged bythe movable contact 90 and thus the glow plugs 12 remain energized.

As mentioned hereinbefore, the relay 7 3 is of the retarded type, this being necessary in order that the bridging of the contacts 96 and 97 on deenergization of the relay 72 may be completed before the circuit, including the contacts 87 and 88, has been opened by the de-energization of the relay 73. Thus the auxiliary circuit through the time controlled thermostat 41 is brought into operation before the relay-7 3 has moved to open the contacts 87 and 88.

The. passage of current through the time" period of time and thus the glow plugs remain hot after the operation of the stprter has been discontinued regardless of the length of time of operation of the starter.

It may be found desirable to reduce the period of operation of the i the engine is hot to furt er prolon the life of the glow plugs and the source 0 supply. This may be done by fitting the time controlled element 41 in a suitable casing 104 and inserting this casin in a recess 105 in ition means when the cylinder wall or cylinder head 107. S0

long as the temperature of the motor is sufii-' ciently high to ensure combustion, the bi- It will be observed that'in this modified form the ignition means will always be active during operation of the starter and during this period is entirely independent of the thermostatic control.

lt will'he appreciated that the foregoing detailed description of the invention has been given to facilitate an understanding of the inventive principles as embodied in the particular arrangementishown in the drawing and that such modification of the elements shown and described herein are content plated as fall within the spirit and scope of the appended claims.

Hav ng thus described the invention, what is claimed as new and desired to he moored by Letters Patent is: p

1. lln aninternal combustion engine, the

combination with an engine starter, of a p source of electric current, means including a starter switch associated with said source and starter'tor energizing said starter when the switch is operated, fuel ignition means associated with said engine, means'for supplying current to said fuel ignition means when the starter switch is operated, and time-controlled means for rendering said last named means inoperative.

2. In an internal combustion engine, the combination with means for driving said engine for starting purposes, of an electrical c1rcuit including a source of supply for energizing said engine driving means, control means for rendering said c1rcu1t operative or moperative, a device for supplying heat to the combustible fuel mixture, and time-controlled means associated with said electrical circuit and said device and rendered operative when said engine driving means is energized for maintaining said device in operation for a predetermined time.

3. In an internal combustion engine, the

combination with an engine starter, of means for' supplying current to said starter,-said means including a switch, means for supplying heat to the combustible mixture for startin a time-controlled relay for controlling said last named means, and connections between said switch and relay for initiating operation of the latter.

4. 111a Diesel engine, the combination with an engine starter, of ignition means of the incandescent type for supplying heat to said engine for starting, starter control means movable to a position for energizing said starter, means operable by said starter con- 7 means operative, and time controlled means acting independently of said switch for thereafter maintaining said ignition means operative for a predetermined period of time.

6. In an internal combustion engine, the combination with an engine starter, of a relay for controllingoperation of said starter, fuel ignition means of the incandescent type, a relay for controlling operation of said ignition, means, a switch for energizing both of said relays, and time controlled means for maintaining energization of said second named relay for a predetermined interval of time.

7'. In an internal combustion engine, the combination with an electrically'operated engine starter, of fuel ignition means of the incandescent type, a source of current supply, a circuit including said source and starter and a circuitincluding said source and ignition means, current controlled means in each circuit for opening and closing said circuits, a main switch for controlling the supply of current'to said current controlled means,an auxiliary circuit including a time controlled element for suppl 'ng current to the current controlled means in the circuit for saidignition means,- and means for rendering saidauxilia circuit. active when said main switch isclos s 8, In an internal combustion engine, the

combination with an electrically operated engine starter, of fuel ignition means of the incandescent t pe, a source of current. supply,

- a circuit inclu 'ng said source and starter and a circuit including said source and ignition means, current controlled means in each circuit for opening and closing said circuits, a main switch for controlling the supply of current to said current controlled means, an

- auxiliary circuit including a time controlled element for supplyin current to the current controlled means in t e circu tfor sald ignition means, and means for rendering said auxiliary circuit active when said main switch is opened to open said starter circuit, whereby said ignition means will remain energized for a period of time thereafter. a

9. In an internal combustion engine, the combination with an electrically operated engine starter, of fuel ignition means of the incandescent type, a source of current supply, a relay for said starter, a relay for said ignition means, a switch for energizing said relays, time controlled' means bypassing said switch for energizing said ignition relay, and means operable by said switch for rendering said time controlled means operative.

10. In an internal combustion engine, the combination with an engine starter, of means for supplying current to said starter, said means including a switch, means for supplying heat to the combustible mixture for starting, a time-controlled relay for controlling said last named means, and connections between said switch and relay for initiating operation of the latter, and means whereby said time-controlled relay is rendered inoperative when the engine temperature is sufliciently high for starting purposes. 7

11. In an internal combustion engine, the combination with an engine starter, of a relay for controlling operation of said starter, fuel ignition means of the incandescent type, a relay for controlling operation of said ignltion means, a switch for energizing both of said rela s, means for maintaining energization 0 said second named relay for a predetermined interval of time, and means whereby said last named means is rendered inoperative when the engine temperature is sufliciently high for starting purposes. v

12. In an internal combustion engine, the combination with an engine starter, of a source of electric current, means including a starter switch associated with said source and starter for energizing said starter when the switch is operated, fuel ignition means associated with said engine, means for sup: plying current to said fuel ignition means when the starter switch is operated, and timecontrolled means for maintaining the supply and time controlled mechanism associated with said lastvnamed means for terminating the energization of said last named gne'ans.

Ill

instigate continuously operated incandescent type, of

an electrical circuit including a source of supply for energizing said means for starting purposes,anda thermostatic element included in saidcircuit and operable in response to a temperature change for opening the said circuit, said thermostatic element being heated by electrical energy flowing in said circuit.

16. In an internal combustion engine, the combination with fuel ignition means of the continuously operated incandescenttype, of an electrical circuit including a source of supplyfor energizingsaid means for starting purposes, and a thermostatic element included in said circuit and operable in response to a temperature change for opening the said circuit, said thermostatic device being so posi-' tioned as to receive heat from the engine for operation thereof.

In testimony signature.

.ADOLF A. WIDMANN.

whereof I hereunto afiix my 

